This study aimed to define the role of the lateral X-ray in the assessment and treatment planning of proximal femoral fractures. Occult fractures were not included.Radiographs from 359 consecutive patients with proximal femoral fractures admitted to our emergency department over a 12 month period were divided into anteroposterior (AP) views and lateral views. Three blinded reviewers independently assessed the radiographs, first AP views alone then AP plus lateral views, noting the fracture classification for each radiograph. These assessments were then compared with the intra-operative diagnosis, which was used as the gold standard. A 2 × 2 contingency square table was created and Pearson's χ(2) test was used for statistical analysis.The rate of correct classification by the reviewers was improved by the assessment of the lateral X-ray in addition to the AP view for intracapsular fractures (p<0.013) but not for extracapsular fractures (p=0.27). However, the only advantage obtained by assessing the lateral view in intracapsular fractures was the detection of displacement where the fracture appeared undisplaced on the initial AP view.This study provides statistical evidence that one view is adequate and safe for the majority of hip fractures. The lateral radiograph should not be performed routinely in order to make considerable savings in money and time and to avoid unnecessary patient discomfort.
1 * Abstract: A method for the synthesis of nonionic surfactants - N-alkyl-O-(2- hydroxyethyl) carbamates is proposed by acylation of fatty amines with ethylene carbonate without any solvent or catalyst. The surface tension of the prepared surfactants was measured, toxicity and biodegradability were determined for the surfactant with n-dodecyl as a hydrophobic group and N-monosubstituted amide and hydroxyl groups for their hydrophilic part.
Background: The optimal method for arthroscopic rotator cuff repair is not yet known. The hypothesis of the present study was that a double-row repair would demonstrate superior static and cyclic mechanical behavior when compared with a single-row repair. The specific aims were to measure gap formation at the bone-tendon interface under static creep loading and the ultimate strength and mode of failure of both methods of repair under cyclic loading. Methods: A standardized tear of the supraspinatus tendon was created in sixteen fresh cadaveric shoulders. Arthroscopic rotator cuff repairs were performed with use of either a double-row technique (eight specimens) or a single-row technique (eight specimens) with nonabsorbable sutures that were double-loaded on a titanium suture anchor. The repairs were loaded statically for one hour, and the gap formation was measured. Cyclic loading to failure was then performed. Results: Gap formation during static loading was significantly greater in the single-row group than in the double-row group (mean and standard deviation, 5.0 ± 1.2 mm compared with 3.8 ± 1.4 mm; p < 0.05). Under cyclic loading, the double-row repairs failed at a mean of 320 ± 96.9 N whereas the single-row repairs failed at a mean of 224 ± 147.9 N (p = 0.058). Three single-row repairs and three double-row repairs failed as a result of suture cut-through. Four single-row repairs and one double-row repair failed as a result of anchor or suture failure. The remaining five repairs did not fail, and a midsubstance tear of the tendon occurred. Conclusions: Although more technically demanding, the double-row technique demonstrates superior resistance to gap formation under static loading as compared with the single-row technique. Clinical Relevance: A double-row reconstruction of the supraspinatus tendon insertion may provide a more reliable construct than a single-row repair and could be used as an alternative to open reconstruction for the treatment of isolated tears.
Differentially substituted 1,3-diaryl-substituted allylic cations generated by ionization of the corresponding allylic alcohols in the presence of a Lewis acid undergo chemoselective and regioselective electrocyclization reactions to generate 1-aryl-1H-indenes. Electrocyclization only occurs for allylic cations bearing a 2-substituent, with 2-ester and 2-alkyl substituents both tolerated. In general, the presence of electron-withdrawing substituents deactivates the ring and disfavors cyclization. In contrast, the selectivity of cyclization of systems containing electron-donating substituents depends on the nature and position of the electron-donating group. Electron-donating substituents at the meta position particularly favor cyclization. There was no obvious correlation of cyclization selectivity with calculated electron densities as has been suggested for electrophilic aromatic substitution reactions. However, the calculated selectivities determined by a gas-phase (B3LYP/6-31G* + ZPVE) comparison of the relative rates of cyclization were in remarkably good agreement with the observed selectivities. Calculated transition-state structures for cyclization are consistent with a cationic pi4(a) conrotatory electrocyclization mechanism. In some cases involving more electron-deficient systems, the initially formed 1H-indene underwent subsequent alkene isomerization to the 3H-indene. In one example, an unusual dimerization reaction occurred to give a cyclopenta[a]indene via an unusual formal cationic 2pi+2pi cycloaddition of the allylic cation with the intermediate indene.
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